1. Field of the Invention
The invention concerns a wood floor, comprising a hardenable of curable adhesive which is coated as a continuous layer onto a floor base, and covering elements of wood or a wood material that are bonded to the adhesive over their entire surface to be glued.
2. Description of the Related Art
For adhering covering elements used to make parquet or inlay floors, adhesives are conventionally employed which are comprised of natural and/or synthetic resins and include suitable solvents and additives. According to applicable DIN (German Industrial Standard) 218, the parquet adhesives exhibit a shear strength of at least 3 to 3.5 N/mm2, which results in a hard and brittle junction of the covering elements to the base floor. The adhesive is applied using a toothed trowel. When laying the parquet floor, attention must be paid to the fact that the parquet wood expands when absorbing moisture and shrinks when (re)drying. The parquet wood conventionally contains 9% water during the laying process. The moisture content can change due to water uptake in a new construction through the sub-floor, or from the environment, or as a result of the variable humidity depending upon the season. The expansion and shrinking caused thereby must be absorbed or accepted by the adhesive material. Thereby, substantial shear forces result. These shear forces can in certain cases result in a bowing out of the parquet wood or result in gaps or formation of splits. In the case of breakage it frequently occurs that not only the adhesive joint but rather also the sub-floor comprised of cement is damaged. This is due to the fact that the shear strength of the cement floor is relatively low in comparison to the parquet adhesive according to DIN 281. On the other hand, during drying the parquet pieces shrink. Since the parquet adhesive does not permit a shrinking at the point of adhesion, frequently large gaps occur between the parquet pieces.